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Hi, I'm Hillel. This is the newsletter version of [my website](https://www.hillelwayne.com). I post all website updates here. I also post weekly content just for the newsletter, on topics like * Formal Methods * Software History and Culture * Fringetech and exotic tooling * The philosophy and theory of software engineering You can see the archive of all public essays [here](https://buttondown.email/hillelwayne/archive/).
Site URL: buttondown.com/hillelwayne
Feed URL: buttondown.com/hillelwayne/rss
Posts: 11
Followers: 2
Free Books
https://buttondown.com/hillelwayne/archive/free-books/
Published: March 3, 2026 16:34
Spinning a lot of plates this week so skipping the newsletter. As an apology, have ten free copies of Logic for Programmers. These five are available now. These five should be available at 10:30 AM CEST tomorrow, so people in Europe have a better chance…
New Blog Post: Some Silly Z3 Scripts I Wrote
https://buttondown.com/hillelwayne/archive/new-blog-post-some-silly-z3-scripts-i-wrote/
Published: February 23, 2026 16:49
Now that I'm not spending all my time on Logic for Programmers, I have time to update my website again! So here's the first blog post in five months: Some Silly Z3 Scripts I Wrote. Normally I'd also put a link to the Patreon notes but I've decided I don't…
Stream of Consciousness Driven Development
https://buttondown.com/hillelwayne/archive/stream-of-consciousness-driven-development/
Published: February 18, 2026 16:33
This is something I just tried out last week but it seems to have enough potential to be worth showing unpolished. I was pairing with a client on writing a spec. I saw a problem with the spec, a convoluted way of fixing the spec. Instead of trying to…
Proving What's Possible
https://buttondown.com/hillelwayne/archive/proving-whats-possible/
Published: February 11, 2026 18:36
As a formal methods consultant I have to mathematically express properties of systems. I generally do this with two "temporal operators": A(x) means that x is always true. For example, a database table always satisfies all record-level constraints, and a…
Logic for Programmers New Release and Next Steps
https://buttondown.com/hillelwayne/archive/logic-for-programmers-new-release-and-next-steps/
Published: February 4, 2026 14:00
It's taken four months, but the next release of Logic for Programmers is now available! v0.13 is over 50,000 words, making it both 20% larger than v0.12 and officially the longest thing I have ever written.1 Full release notes are here, but I'll talk a bit…
Refinement without Specification
https://buttondown.com/hillelwayne/archive/refinement-without-specification/
Published: January 20, 2026 17:49
Imagine we have a SQL database with a user table, and users have a non-nullable is_activated boolean column. Having read That Boolean Should Probably Be Something else, you decide to migrate it to a nullable activated_at column. You can change any of the…
My Gripes with Prolog
https://buttondown.com/hillelwayne/archive/my-gripes-with-prolog/
Published: January 14, 2026 16:48
For the next release of Logic for Programmers, I'm finally adding the sections on Answer Set Programming and Logic Constraint Programming that I TODOd back in version 0.9. And this is making me re-experience some of my pain points with Prolog, which I will…
The Liskov Substitution Principle does more than you think
https://buttondown.com/hillelwayne/archive/the-liskov-substitution-principle-does-more-than/
Published: January 6, 2026 16:51
Happy New Year! I'm done with the newsletter hiatus and am going to try updating weekly again. To ease into things a bit, I'll try to keep posts a little more off the cuff and casual for a while, at least until Logic for Programmers is done. Speaking of…
Some Fun Software Facts
https://buttondown.com/hillelwayne/archive/some-fun-software-facts/
Published: December 10, 2025 18:45
Last newsletter of the year! First some news on Logic for Programmers. Thanks to everyone who donated to the feedchicago charity drive! In total we raised $2250 for Chicago food banks. Proof here. If you missed buying Logic for Programmers real cheap in…
One more week to the Logic for Programmers Food Drive
https://buttondown.com/hillelwayne/archive/one-more-week-to-the-logic-for-programmers-food/
Published: November 24, 2025 18:21
A couple of weeks ago I started a fundraiser for the Greater Chicago Food Depository: get Logic for Programmers 50% off and all the royalties will go to charity.1 Since then, we've raised a bit over $1600. Y'all are great! The fundraiser is going on until…
Get Logic for Programmers 50% off & Support Chicago Foodbanks
https://buttondown.com/hillelwayne/archive/get-logic-for-programmers-50-off-support-chicago/
Published: November 10, 2025 16:31
From now until the end of the month, you can get Logic for Programmers at half price with the coupon feedchicago. All royalties from that coupon will go to the Greater Chicago Food Depository. Thank you!